1. Field of the Invention
This invention relates generally to electronic mailing systems. The invention relates more particularly to an improved electronic mailing apparatus and method for determining postage for variations within a class of postal service.
2. Description of the Prior Art
Various systems have been provided for automatically calculating postage. These systems in general make use of electronic computational techniques. One such system to which the present invention pertains is disclosed in U.S. Pat. No. 4,286,325 which is assigned to the assignee of this invention. In the system disclosed in the aforementioned patent, postage for each class of domestic service is automatically determined on the basis of the particular class of service, the destination zone and the weight of a parcel being mailed. Other factors are also automatically accounted for, as for example, over-sized parcels, over-weight parcels, etc. The system includes a scale means which provides a digitally encoded indication of the weight of the parcel, a user terminal means for manually entering the desired class of service and destination zip code, a memory means for storing program and postage rate information, and a processor which intercouples the scale, terminal and memory means to provide calculated postage for the parcel. The postage amount thus determined is displayed and, when desired, is automatically printed.
With a selected class of service and a predetermined parcel weight, the variable which controls the domestic postage charge is the destination zone. The U.S. postal service has established eight destination zones each of which encompasses a predetermined range of geographical distances from the point of origin of the parcel being mailed. For example, a zone 3 range of distances encompasses 151 to 300 miles from the point of origin, a zone 5 range of distances encompasses 601 to 1,000 miles from the point of origin, etc.
Parcel handling and processing is facilitated by the familiar use of zip code numbers, each of which is associated with a particular geographic location in the United States. Generally speaking, the average user of the United States postal service is more familiar with zip code usage than zone distances. Accordingly, in order to facilitate a determination of the destination zone from a knowledge of the destination zip code, the United States postal service has established zip code to zone number conversion tables. Each such table in unabridged form may include up to, but generally less than, 256 destination zip code to destination zone number conversions. One such conversion table is required for a limited area of originating zip codes. In practice approximately 600 such tables are employed to cover existing originating zip codes in the United States. By referring to the appropriate originating zip code table, the user can readily locate the destination zip code and he will learn the corresponding destination zone. Having thus learned the destination zone number, the user need only enter a postage table for the desired class of service with the known parcel weight to determine the established postage. It is apparent that the use of zip to zone tables thus facilitates manual postage computation.
The electronic mailing system disclosed in the aforementioned patent automatically performs this operation. It includes stored data in its memory means which encompasses some of the aforementioned zip to zone conversion tables. While a relatively large storage capacity would be required to store the data for 600 standard/express conversion tables, the storage requirements for a system at a particular location have been reduced by storing a limited number of conversion tables including the tables for the system locale and by providing selective switching means for indicating the storage table associated with the geographic locale of the system. In operation, the user of the existing system disclosed in the aforementioned patent makes a keyboard entry of the first three digits of the destination zip code and the processor, through a predetermined routine, obtains the destination zone from the stored zip to zone conversion tables and automatically uses the zone thus found in computation of the postage.
The postage for fourth-class service is computed on a zone and weight basis as indicated hereinbefore. In establishing zone costs for fourth-class service, the United States postal service has geographically divided the United States into a number of bulk mailing centers (BMCs). In practice, fourth-class mail is routed from a point of origin to the nearest BMC, from this nearest BMC to the destination BMC, and thence from the destination BMC to a destination address. Fourth-class zone rates reflect this BMC form of parcel handling. However, there are occasions when both the destination address and point of origin are located in an area encompassed by the same BMC. In such case, transportation from the originating BMC to the destination BMC is unnecessary and associated handling is avoided. Under these circustances, the postage for intra-BMC mailing is less than the fourth-class postage as reflected in the zone distance costs for fourth-class service and represents a variation from the cost of fourth-class service as determined on the basis of weight and zone distance.
It would be beneficial to provide a method and apparatus for use with an electronic mailing system of the type disclosed in the aforementioned patent which reflects a reduction in postage for intra-BMC parcel handling. It would also be beneficial to provide a method and apparatus for use with systems of the type disclosed in the aforementioned patent which adapts such existing systems to reflect the reduced postage for intra-BMC parcel handling. While such a system may be provided through the use of a separate zip to zone conversion table, it would be relatively costly and complex to provide a separate storage means for each of the approximately 600 separate conversion tables.